this post was submitted on 08 Dec 2024
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[–] [email protected] 41 points 3 days ago (4 children)

Don’t forget this one https://en.m.wikipedia.org/wiki/Mars_Climate_Orbiter

An investigation attributed the failure to a measurement mismatch between two measurement systems: SI units (metric) by NASA and US customary units by spacecraft builder Lockheed Martin.

Oops

[–] partial_accumen 25 points 3 days ago (1 children)

Mars Climate orbiter holds the record I think for coding problem and spacecraft failure. That one cost $460m.

A great runner up would be the loss of the maiden flight of the new Ariane 5 rocket at $370m:

"On June 4th, 1996, the very first Ariane 5 rocket ignited its engines and began speeding away from the coast of French Guiana. 37 seconds later, the rocket flipped 90 degrees in the wrong direction, and less than two seconds later, aerodynamic forces ripped the boosters apart from the main stage at a height of 4km. This caused the self-destruct mechanism to trigger, and the spacecraft was consumed in a gigantic fireball of liquid hydrogen.

The disastrous launch cost approximately $370m, led to a public inquiry, and through the destruction of the rocket’s payload, delayed scientific research into workings of the Earth’s magnetosphere for almost 4 years. The Ariane 5 launch is widely acknowledged as one of the most expensive software failures in history. What went wrong?

The fault was quickly identified as a software bug in the rocket’s Inertial Reference System. The rocket used this system to determine whether it was pointing up or down, which is formally known as the horizontal bias, or informally as a BH value. This value was represented by a 64-bit floating variable, which was perfectly adequate.

However, problems began to occur when the software attempted to stuff this 64-bit variable, which can represent billions of potential values, into a 16-bit integer, which can only represent 65,535 potential values. For the first few seconds of flight, the rocket’s acceleration was low, so the conversion between these two values was successful. However, as the rocket’s velocity increased, the 64-bit variable exceeded 65k, and became too large to fit in a 16-bit variable. It was at this point that the processor encountered an operand error, and populated the BH variable with a diagnostic value."

source

The kicker on this one was the bug was copied from the previous successful Ariane 4 rocket code, but the Ariane 4 never experienced it because the Ariane 4 first stage was dropped in each flight before the bug would show itself, so it was never an issue there. Because the Ariane 5 had a slightly different flight profile it was in the air a longer period of time...enough time to experience the bug and cause a loss of the rocket in flight.

[–] [email protected] 16 points 3 days ago

Static type checking ftw

[–] Bacano 16 points 3 days ago* (last edited 3 days ago) (1 children)

I'll keep it going:

Don't forget about the time Initech had it's credit union hacked with a virus that was supposed to only take a negligible percentage of each transaction but the programmer figured he must have "put the decimal in the wrong place or something."

The group got away under pretty mysterious circumstances...

[–] slingstone 7 points 3 days ago

Didn't their corporate office burn down afterwards? Suspicious indeed...

[–] Psythik 3 points 3 days ago (2 children)

Why the fuck is/was NASA using the US customary system? Science is always done in metric, even in the US.

[–] Anticorp 15 points 3 days ago* (last edited 3 days ago)

It says NASA was using metric, Lockheed Martin used imperial. Read it again.

[–] gerbler 6 points 3 days ago

IIRC they had outsourced to a contractor and that contractor was using imperial

[–] subtext 1 points 3 days ago* (last edited 3 days ago)

~~It was just a simple transposition right? 2.45 (wrong) vs 2.54 (right)~~

E: never mind, I was wrong